Centrifugal switch



June is, 1936.

Original Filed Dec. 15; 1953 INVENTOR. Charles B Emfone fluke/1M- Jameson Patented June 16, 1936 UNITED STATES PATENT OFFICE CENTRIFUGAL SWITCH tion of New Jersey Original application December 15, 1933, Serial No. 702,520, now Patent No. 2,003,353, dated June 4, 1935.

Divided and this application April 30, 1935, Serial No. 19,056

6 Claims.

This invention relates to improvements in centrifugal switches particularly of the type employed upon machines for applying in a helical wrap a web or tape of material about a longitudinally advancing core.

More particularly the invention has for its object a positive acting centrifugal switch espe cially adapted for use on electrical wire insulating machines.

These and other objects are successfully secured by means of this invention.

The switch of this invention is broadly applicable to any machine for wrapping a web around a core. More particularly it is adapted foruse on a machine of the type disclosed in our Patent No. 1,955,908, issued April 24, 1934 on our copending application, Serial No. 634,350, filed September 22, 1933.

This application is a division of our copending application Serial No. 702,520, filed December 15, 1933, now Patent No. 2,003,353 for Automatic stop device.

This invention resides substantially in the combination, construction, arrangement and relative location of parts all as will be described in full detail below.

In the drawing,

Figure l is a cross sectional view through one form of switch in accordance with this invention and showing in cross section the supporting guide-post for the web or tape and apart of the support therefor which is adapted to be rotated on a fixed axis;

Fig. 2 is an enlarged detail view of the switch in one position as distinguished from its closed position illustrated in Figure 1;

Figs. 3 and 4 are elevational views of a modified form of switch shown in closed and open position respectively;

Figs. 5 and 6 show plan and side elevational views respectively of a further modified form of switch in closed position;

Fig. 7 is a view similar to Fig. 6 showing the switch in open position;

Fig. 8 is an elevational View, partly in. cross section of a still further modified form of switch, and is shown in closed position;

Fig. 9 is a plan view of this switch showing some parts in cross section;

Fig. 10 is a similar View showing this switch in open position;

Figs. 11 and 12 are side elevational views partly in cross section of another modification of the switchshown in open and closed positions respectively.

In machines for wrapping a web around a longitudinally advancing core, such as a wire insulating machine, it is of paramount importance that the machine stop as quickly as possible upon the breakage of the web. The core or wire is advanced at a rapid rate and when the web breaks it is apparent that a considerable length of wire may pass through the machine before it is brought to a stop. This is of course highly undesirable. The centrifugal switch of this invention is adapted for use in such machines and is of such construction as to insure dependable, positive, actuation when the web breaks to bring the machine to a stop by controlling directly or indirectly the circuits of the operating motor.

In Figure 1 the support I!) as shown is but a part of the rotatable support or serving head which revolves upon a fixed axis. Mounted upon this support is a spindle or standard 13 which is locked in place thereon by means of the nut 11. This spindle has a longitudinal bore therethrough in which lies the insulated conductor 30 forming one leg of the control circuit. An insulating bushing 22 is provided to reduce danger-of short circuit of this wire on the frame of the machine which is normally grounded to form the other leg of the control circuit. Rotatably mounted on the spindle I3 is the guide sleeve l8 around which the web 16 passes in travelling from the supply spool to the point of application.

The upper end of spindle i3 is counterbored to receive a screw 20 which looks a collar 19 onto the spindle. The screw 20 in turn has a hole through the center thereof in which is mounted the insulating bushing 2| likewise centrally bored. Mounted in the bore of the bushing 2|, is a contact 23 which is connected to the wire 30. Supported upon the collar I9 is an arm 24 on which is pivotally supported at 25, a lever 26. Slidably mounted in one end of this lever is a contact 21 which cooperates with the contact 23 and which is resiliently urged into engagement with that contact by means of a flat spring 28 mounted on the lever 26. Secured to the other end of lever 25 is an extension arm 29 terminating in a contact portion against which the web 16 bears.

An important feature of this invention resides in the fact that the extension arm 29 lies at a slight angle below the longitudinal axes of the lever 26. This angle should be at least approximately five degrees. The purpose of extending the arm 29 along the line below the horizontal axes of lever 26, is to insure a positive tendency of the arm to rotate downwardly under the centrifugal forces encountered when the support It) revolves at the normal and high speed of operation of such machines. The web [6, as it is fed from the supply spool to the point of application is under tension and engaging the end of arm 29 holds it in the position shown in Figure 1 against its tendency to move to the position shown in Fig. 2.

When the web breaks however, the arm positively and instantaneously swings downwardly, see Fig. 2, moving contact 21 out of engagement with contact 23. This breaks either the motor circuit which causes operation of the machine and rotation of support Ill, or the control circuit of a control device in the motor circuit. As is previously stated, the other leg of the control circuit is grounded on the machine.

The resilient connection between contact 21 and lever 26, does not interfere with the operation of the device and does not open the circuit even though there may be variation in the tension of the web 16 as it is being fed to the point of application. In other words, by this construction lever 26 may undergo some movement under the changing tension in the tape 16 without prematurely breaking the circuit connected thereto.

The modified forms of stop switch structure will now be described. In the arrangement of Figs. 3 and 4, the pivot point 25a. for the lever 26a, is pivoted to one end. A spring 54 is employed to tend to cause the switch to open. In this case, the web l6 passes over the top of arm 29a so that it will hold the switch closed against the action of spring 59 in normal operation. In this case the axis of arm 29a. lies above the longitudinal axis of lever 26a. Here again the requirement that this arm extend at an angle of at least approximately five degrees with the axis of lever 26a holds. In this case, however, the angle is above the horizontal as distinguished from being below the horizontal in the form of switch shown in Figure 1. Although the position of this structure is immaterial in the operation of the device, it might be noted that the preferred position would be at right angles to that shown in Figs. 3 and 4 in the plane of the paper in a manner similar to the arrangement shown in Figure 1. This observation likewise applies to the other modifications to be described.

Figs. 5, 6 and 7 illustrate a modification particularly adapted for use with a web which is in the form of a thread or cord. In this case, the arm 26b is pivotally mounted intermediate its ends in a manner similar to the structure of Figure 1. However, the arm 29, instead of extending from the end of lever 26b, is pivotally mounted on the arm 24b below the pivot point 25b. The lower end of lever 25?) is grooved so that arm 29 may rest therein. In this case, the cord l6 passes up through the aperture in the enlarged end 29 of lever 29'. Figure 7 shows the position of the parts in the event of the breakage of the cord.

The modification of Figs. 8, 9 and 10 differs from the structures previously described in that the axis of the pivot 250 is vertical instead of horizontal. In this case, the lever 26c swings in a horizontal plane and the contact 23c in this form of structure, is mounted in this case upon an L-shaped bracket which is supported in the insulating bushing 2| and which is connected to wire 30. In this case the web holds the switch closed and upon breakage the action of centrifugal force will cause the switch to open. The lever 26c operating in a horizontal plane will be thrown open by centrifugal force even though the axis of the arm 29c coincides with the axis of lever 260. In other words, the two axes do not need to lie at an angle.

The final modification is illustrated in Figs. 11 and 12. In this case, the contact 23d is mount- 5 ed upon a bracket 55' so as to be supported above the contact 2101. In this case, the web I6 bears on the upper surface of the arm 29d and normally holds it in the position shown in Fig. 11. With this form of device, the axis. of arm 29d again 10 extends at an angle and to one side of the axis of lever 26d.

In all these forms of switches, it will be noted that contact 23, 23c and 23d is insulated from the machine frame while contact 21 and 21d, 15 is connected directly to the machine frame which, as stated, is grounded. Likewise, the contact 21 and 21d is slidably mounted in its support so that the support may be free to move under varying conditions of operation produced by varia- 20 tions in the tension of the web without interfering with the circuit which includes this contact. Likewise, this free movement of the support insures that the web will not be broken by reason of its engagement with the arm 29, 29c, 2919,25 29c and 29d.

The support 10 forming part of a conventional serving head revolves at high speeds upon a fixed vertical axis so. that the spindle or standard I3 revolves in a circular path about that fixed axis. 30 The centrifugal switch being supported on the standard l3 must, therefore, travel in a circular path at a high rate of speed around that fixed axis. As a result when the web l6 breaks the arm 29 (Figures 1 and 2), which is now released, 35 snaps downwardly or in other words tends to fly out into a radial position with respect to the main axis of rotation. It is biased to. swing downwardly by reason of the fact that a portion of its axis is at an angle to the horizontal. The 40 arrangements of Figures 11 and 12 work similarly.

In the arrangement of Figure 3 the arm obviously swings upwardly when the web l6 breaks (see Figure 4). In the arrangement of Figures 45 8, 9 and 10 the arm swings in a counter clockwise direction about 25 for a clockwise direction of rotation of the support 10, i. e., the serving head.

From the above description it will be apparent that this invention resides in certain fea- 50 tures of construction which may be embodied in other physical forms and carried out in other ways without departure from the scope thereof. We do not, therefore, desire to be strictly limited to the disclosure as given for purposes of 55 illustration, but rather to the scope of the appended claims.

What we seek to secure by United States Letters Patent is:

1. A centrifugally operated switch comprising a support adapted to be rotated about a fixed axis spaced therefrom. a contact mounted on the support and insulated therefrom, a lever pivotally mounted on the support and having a portion extending at an angle with respect to the remainder thereof, and a contact mounted on said lever and engageable with the first mentioned contact, said extension forming a strand guide.

2. A centrifugally operated switch as described comprising a support adapted to be rotated about a fixed axis spaced therefrom, an insulated contact mounted on the support, a lever pivotally mounted on the support having an extension lying at an angle with the axis of the lever, a contact slidably mounted on the lever and a spring engaging the slidable contact to resist movement thereof when it engages the insulated contact, said lever being held against movement by a strand guided by the extension.

3. In a switch as described the combination comprising a support adapted to be rotated about a fixed axis spaced therefrom, a contact mounted on said support and insulated therefrom, a lever pivotally mounted on the support having a contact thereon for engagement with said first mentioned contact, the longitudinal axis of said lever lying in a substantially horizontal plane when the contacts are engaged, an extension on said arm lying at an angle below the horizontal and the pivoted point of said lever being between the ends thereof.

4. A centrifugal switch as described, comprising a support adapted to be rotated about a fixed axis, a contact mounted on said support and insulated therefrom, a lever pivotally mounted at one end on said support, a contact slidably mounted on said lever intermediate the end thereof so as to be engageable with said first contact and a web guiding extension mounted on the other end of said lever and extending at an angle with the longitudinal axis of said lever.

5. A centrifugal switch as described comprising a support adapted to be rotated about a fixed axis, a contact mounted on said support and insulated therefrom, an arm pivotally mounted intermediate its ends on said support, a contact mounted on said arm near one end thereof, and a second arm pivotally mounted on said support and engageable intermediate its ends with the other end of said first arm.

6. A centrifugal switch as described comprising a support adapted to be rotated about a fixed axis, a contact mounted on said support and insulated therefrom, an arm pivotally mounted intermediate its ends on said support, a contact mounted on said arm near one end thereof, a second arm pivotally mounted on said support and engageable intermediate its ends with the other end of said first arm, the contact on said 20 arm being slidably mounted thereon and a spring for resisting movement in one direction thereof.

CHARLES B. FANTONE. REUBEN M. JAMESON. 

